This silent film from the 1950s shows Western doctors, presumably associated with the London School of Hygiene and Tropical Medicine, working to eradicate certain tropical diseases in East Africa. In South West Uganda we see people lining up to see a doctor, having a piece of skin removed (a 'skin snip) for examination to see if there are any 'microfilariae'. We see panoramic shots of the countryside and inter-titles tell us about which kinds of places are high breeding grounds for 'S. Damnosum' and 'S. Neavei'. The majority of the film then consists of showing us how S. Neavei was eradicated from a river using DDT. 1 segment.